Gas insufflating means for a molten metal refining container



NOV 17, 1970 TAKATERU NoMuRA ETAL 3,541,604

GAS INSUFFLATING MEANS FOR A MOLTEN METAL REFINING CONTAINER Filed Jan. 2z. 196e lll TAKATERU NDMURA MID MoHEl sumaba,

INVENTORS ATTOR NEYS United States Patent O Int. el. C21c 7/00 U.S. Cl. 266-34 4 Claims ABSTRACT F THE DISCLOSURE Gas insufiiating means for a metal refining container. The means is formed providing a gas-permeable porous refractory and a perforated supporting brick in layers so as to obtain a sufficient gas jetting force and a high safety in the gas inlet hole.

BACKGROUND OF THE INVENTION Field of the invention This invention relates generally to molten metal containers having porous refractory plugs and more particulary to refining gas inlet insufliating devices for molten metal containers.

Description of the prior art Generally, in order to add and uniformly mix various alloy additives to a molten metal contained in a refining container or to add various refining agents to desulfurize the molten metal, a gas is often blown into the molten metal so that said molten metal may be agitated or its catalytic reaction with said refining agents may be improved.

In carrying out such operation as is mentioned above, there is known an insuiiiating device wherein a gas-permeable porous firebrick is placed in the side wall of a molten metal container or in the bottom of said container so that an agitating gas or reaction gas may be blown in through said rebrick.

However, the molten metal often leaks out through such refractory lining of such porous firebrick as is mentioned above.

In order to prevent such an accident, the chemical and mechanical strength of said porous refractory has been greatly improved. Nevertheless, serious accidents have occurred due to the cracking of such porous refractory.

Further, the above mentioned porous refractory has many gas-permeable pores passing from lone surface to the other, and thus has a property that, in case acrack occurs, it will be likely to quickly spread in the direction of the pore, that is, from the inside to the outside of the container. Therefore, the molten metal will liow along the crack until it reaches the outside shell plate of the container and makes a hole in said outside shell plate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a molten metal container having an insuiating device in the form of a porous refractory plug which will prevent cracks from occurring over the entire lining layer as is mentioned above so that the molten metal will not leak out through the porous lining part.

Another object of the present invention is to provide a gas inlet plugging device in which a gas can be jetted into the molten metal with a sufficient jetting force and the safety with respect to the leakage of the molten metal is high.

Patented Nov. 17, 1970 In order to attain the above mentioned objects, the present invention provides an insufiiating a gas inlet part of a container body having a gas-permeable porous refractory and a supporting brick having one or more gaspermeable pores, said supporting brick being on the back of said porous refractory in the direction of the thickness of the wall of the molten metal container.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawings shall be briefly explained.

FIG. 1 is a vertically sectioned view of a plugging device of the present invention.

FIG. 2 is a sectional view on line II--II in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention shall be explained in detail with reference to the drawings.

In FIG. 1 showing a vertically sectional View of a gas inlet insuiating device in a molten metal container of the present invention, a porous refractory plug member 1` having through pores is fitted in a gas inlet of a container lining layer 4 of molded firebrick and has one end surface directly in contact with said molten metal 12 on the wall surface or in the bottom of said molten metal container.

A refractory supporting brick 2 having gas pores 3 supports said porous refractory plug member 1 on the other end surface from that which is in contact with the molten metal 12. This supporting brick 2 is provided with the above mentioned gas pores 3 for feeding an amount of gas required to be blown into the container to the surface of the porous refractory 1. The size and number of said gas pores 3 are selected depending on the size of the porous refractory plug member 1. That is to say, when the area of said other end of the porous refractory plug member 1 is large, it will be preferable to uniformly distribute the gas pores 3 over the entire area of the supporting brick 2 and therefore the size of the gas-permeable pores 3 should be made as small as possible to improve the strength of the supporting brick 2. On the other hand, when the said other end of the porous refractory plug member 1 is not so large, it will be sufficient to provide only one gas pore 3 in the central part. In such case, it will be necessary to make said pore 3 large enough to pass the desired amount of gas. Further, the gas pores 3 can be concentrated in the central part of the supporting brick 2. If only one gas pore 3 is to be provided or the gas pores 3 are to be concentrated in the central part, it is necessary to provide ribs 5 on the surface of either the supporting brick 2 or the porous refractory plug member 1 so that inlet gas distributing space 6 will be formed. Such space can have any convenient form.

An outside shell plate 7 is provided on the molten metal container. A protective plate 9 is fixed to the outside of the supporting brick 2 with a packing 8 between the plates 9 and 7. The outside of brick 2 has a distributing space 10 for the inlet gas.

Further, the protective plate 9 is provided with a gas inlet pipe 11 adapted to be connected to a source of gas (not illustrated).

The above mentioned porous refractory plug member 1 and supporting brick 2 need not be special ones but may any known ones as long as they fit tightly in the gas inlet hole as shown in FIG. l.

In the present invention, as described above, because the perforated supporting brick 2 is arranged and supported on the back of the porous refractory plug member 1, the porous refractory plug member 1 can be made relatively thin. Therefore, the resistance to the passage of the gas to be fed into the container can be made so low that the gas can be ietted into the molten metal with a sufficient jetting force, additives can be uniformly mixed and rening agents can be made to quickly react. On the other hand, because the present gas inlet insulating device is in two layers, there are advantages that, even if a crack occurs in the porous refractory plug member 1, it will not spread to the supporting brick 2 and that there fore, even if the molten metal 12 ows into the porous refractory plug member, it will be stopped by the supporting brick 2.

By providing the present invention in a molten metal rening container, an efficiency and effective safety can be obtained.

What is claimed is:

1. A gas insulating device for a molten metal refining container having a gas inlet hole with an inner and opening into the container and an outlet end opening out of the container, which comprises a gas-permeable porous refractory plug member adapted to fit tightly into the inner part of the gas inlet hole with one end surface di- 20 rectly in contact with the molten metal in the molten metal container, and a supporting brick having at least one gas pore therein and adapted to t tightly in the outer part of said gas inlet hole and against the other end surface of said porous refractory plug member for support- 25 ing said plug member and plugging the outer part of the gas inlet hole.

2. A device as claimed in claim 1 in which said supporting brick has a plurality of gas pores in the central part of the surface opposed to the porous refractory plug member and further has a plurality of ribs and inlet gas grooves on the peripheral part of said surface, the ribs contacting the plug member.

3. A device as claimed in claim 1 in which said porous refractory plug member has a plurality of ribs and grooves on the peripheral part of said other end surface with the ribs contacting said supporting brick.

4. A device as claimed in claim 1 in which said supporting brick has a gas distributing recess on the surface thereof remote from the surface supporting said plug member.

References Cited UNITED STATES PATENTS 2,871,008 1/ 1959 Spire 75-600 X 2,947,527 8/ 1960 Spire 266-34 3,373,986 3/1968 Spire 266-34 FOREIGN PATENTS 577,247 6/ 1959 Canada. 112,980 1/ 1918 Great Britain. 684,048 12/ 1952 Great Britain.

LAVERNE D. GEIGER, Primary Examiner E. J. EARLS, Assistant Examiner 

